Some projects are already in construction, but many are in the planning stages.

They range from the creation of a massive world-class park at the 2,200-acre former Fresh Kills landfill in Staten Island to $50 million for rebuilding an Olympic-size pool and bringing a recreation center to McCarren Park in Williamsburg.

While Parks Commissioner Adrian Benepe touts the administration is making a “record investment” toward improving its 29,084-acre park system, many critics believe the city’s strategy is costing taxpayers ten of millions of dollars each year.

They say New Yorkers would save money in the long term if the city relied more on tax dollars from the general budget to maintain parks regularly. Instead, the city virtually abandons many of its parks and lets others fall apart until they’re so rundown that funds can legally be borrowed through the capital budget to fix them, critics say.

Using capital spending for maintenance is illegal.

“Its astonishing that the city’s elected officials continue to put the public in harms way by allocating a fraction of the expense dollars needed. It simply isn’t a priority,” said Geoffrey Croft, president of the watchdog group New York City Park Advocates.

A Post investigation published yesterday found some city parks are so neglected that they’re soiled by drug dens, homeless camps, prostitutes and illegal chop shops to strip stolen cars.

Besides illegal dumping, among the biggest maintenance problems spotted were the poor conditions of grass fields and faulty water fountains.

With the current downturn of the economy, park advocates warn that the next mayor could kill some capital projects once a term-limited Bloomberg leaves office at the end of 2009.

Up to $1.8 billion is budgeted to be borrowed for park improvements through at least 2012, including the $1.3 billion for projects already planned.

Benepe said he can’t guarantee that some projects won’t be cut but doubts it because “too many community groups were involved in planning these projects and would fight hard to save them.”

Other projects in the works include:

*$80 million to repair the East River Park promenade in Manhattan.

* $65 million to create the city’s largest recreation complex in a park at Flushing Meadows Corona Park in Queens. The 120,000-square-foot complex’s pool opened in February, and its NHL-standard indoor ice hockey rink is set to open this winter.